1. Field of the Invention
The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition capable of undergoing a reaction upon irradiation with an actinic ray or radiation to change in the property, and a resist film and a pattern forming method each using the composition. More specifically, the present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition for use in the production process of a semiconductor such as IC, in the production of a liquid crystal device or a circuit board such as thermal heads, in the fabrication of a nanoimprint mold structure, in other photofabrication processes, or in a lithographic printing plate or an acid-curable composition, and a resist film and a pattern forming method each using the composition.
2. Description of the Related Art
A chemical amplification resist composition is a pattern forming material of forming a pattern on a substrate by producing an acid in the exposed area upon irradiation with radiation such as far ultraviolet light and through a reaction using the acid as a catalyst, changing the developer solubility of the area irradiated with an actinic ray or radiation and that of the non-irradiated area.
In the case of using a KrF excimer laser as the exposure light source, a resin having small absorption in the wavelength region of 248 nm and having a basic framework of poly(hydroxystyrene) is predominantly used as the main component, and this is an excellent system capable of forming a good pattern with high sensitivity and high resolution, compared with the conventional naphthoquinone-diazide/novolak resin system.
On the other hand, in the case where a light source of emitting light at a shorter wavelength, for example, an ArF excimer laser (193 nm), is used as the exposure light source, a satisfactory pattern cannot be formed even by the above-described chemical amplification system, because the compound having an aromatic group substantially has large absorption in the region of 193 nm.
In order to solve this problem, a resist composition for ArF excimer laser, containing a resin having an alicyclic hydrocarbon structure, has been developed.
Furthermore, a resist composition for forming a fine pattern of several tens of nm by using an X-ray, an electron beam or EUV (lithography) has been also developed.
The resist composition generally contains a basic compound so that the acid generated from an acid generator upon irradiation with an actinic ray or radiation can be prevented from diffusing into the unexposed area. As such a basic compound, DBU (1,8-diazabicyclo[5.4.0]-7-undecene) and a guanidine compound are known (see, for example, JP-A-11-102065 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), JP-A-2002-23372, Japanese Patent No. 3444844, JP-A-2003-149800).
However, these basic compounds still have many insufficient points and it is demanded to improve the basic compound and thereby develop a photosensitive composition enhanced in terms of scum reduction, pattern profile, sensitivity, line edge roughness (LER) and the like.
In particular, the weight of scum reduction is increased as the pattern profile is reduced. For example, in the lithography with X-ray, electron beam or EUV, the target is formation of a fine pattern in the order of several tens of nm and therefore, an excellent scum reduction performance is particularly required.
Furthermore, the formation of a fine pattern involves a problem that the line width varies depending on the temperature at heating after irradiation with radiation (post exposure bake, PEB). Accordingly, improvement of the PEB temperature dependency is also needed.